Originally Posted by wwjd15
4 track days in total, about 8 hours track driving.
All tranny and LSD fluid are OEM.
Wear looks fine in this initial sample out of your BMW's differential. Universal averages show
typical wear levels for this type of differential after about 30,000 miles on the oil. We don't know how long
you ran this oil but wear is still in the average range, so we'd guess it wasn't much longer than that. Silicon
is on the high side, and this is probably harmless sealer material. If you suspect it's dirt, then check into
where it might be coming from, but we suspect it's not a problem. The viscosity is okay for gear oil. Looks like a nice differential....
Whoa just catching this part. You have 5,000 miles but 30,000 miles of wear on the diff? Is that right?